Eco-Friendly Superhydrophobic Composites with Thermostability, UV Resistance, and Coating Transparency

Advancements in Superhydrophobic Paper-Based Materials: A Comprehensive Review of Modification Methods and Applications

Superhydrophobic paper-based functional materials have emerged as a sustainable solution with a wide range of applications due to their unique water-repelling properties. Inspired by natural examples like the lotus leaf, these materials combine low surface energy with micro/nanostructures to create air pockets that maintain a high contact angle. This review provides an in-depth analysis of recent advancements in the development of superhydrophobic paper-based materials, focusing on methodologies for modification, underlying mechanisms, and performance in various applications. The paper-based materials, leveraging their porous structure and flexibility, are modified to achieve superhydrophobicity, which broadens their application in oil-water separation, anti-corrosion, and self-cleaning. The review describes the use of these superhydrophobic paper-based materials in diagnostics, environmental management, energy generation, food testing, and smart packaging. It also discusses various superhydrophobic modification techniques, including surface chemical modification, coating technology, physical composite technology, laser etching, and other innovative methods. The applications and development prospects of these materials are explored, emphasizing their potential in self-cleaning materials, oil-water separation, droplet manipulation, and paper-based sensors for wearable electronics and environmental monitoring.

A comprehensive review on self-cleaning glass surfaces: durability, mechanisms, and functional applications

Self-cleaning glass surfaces have emerged as a focal point in the field of materials science due to their potential to reduce the accumulation of pollutants, enhance transparency, and improve durability. In recent years, significant advancements have been made in self-cleaning technologies based on photocatalysis and wettability regulation, particularly in the development of superhydrophobic and superhydrophilic surfaces. This article provides a systematic review of the research progress in self-cleaning technologies for glass surfaces. It analyzes and summarizes the applicability of self-cleaning effects induced by special properties such as photocatalysis, superhydrophobicity, superhydrophilicity, and omniphobicity on glass surfaces. Subsequently, the article delves into a discussion of the durability of these surface treatment technologies in practical applications, especially their stability and long-term performance under harsh environmental conditions. Furthermore, the paper explores the current status of applications for self-cleaning glass surfaces across various fields and proposes potential solutions and future research directions to address the challenges encountered in the practical application of self-cleaning glass surfaces.

Water Repellent Coating in Textile, Paper and Bioplastic Polymers: A Comprehensive Review

Water-repellent coatings are essential for enhancing the durability and sustainability of textiles, paper, and bioplastic polymers. Despite the growing use of sustainable materials, their inherent hydrophilicity presents significant challenges. This review explores advanced coating technologies to address these issues, focusing on their mechanisms, properties, and applications. By imparting water resistance and repellency, these coatings improve material performance and longevity. The environmental impact and limitations of current coatings are critically assessed, highlighting the need for sustainable solutions. This review identifies key trends and challenges, offering insights into developing water-resistant materials that align with environmental goals while meeting industry demands. Key focus areas include coating mechanisms, techniques, performance evaluation, applications, environmental impact assessment, and the development of sustainable coating solutions. This research contributes to the development of water-resistant materials that meet the demands of modern industries while minimizing environmental impact.

Green and Abrasion-Resistant Superhydrophobic Coatings Constructed with Tung Oil/Carnauba Wax/Silica for Wood Surface

As a renewable, environmentally friendly, natural, and organic material, wood has been receiving extensive attention from various industries. However, the hydrophilicity of wood significantly impacts the stability and durability of its products, which can be effectively addressed by constructing superhydrophobic coatings on the surface of wood. In this study, tung oil, carnauba wax, and silica nanoparticles were used to construct superhydrophobic coatings on hydrophilic wood surfaces by a facile two-step dip-coating method. The surface wettability and morphology of the coatings were analyzed by a contact angle meter and scanning electron microscope, respectively. The results suggest that the coating has a micron-nanosized two-tiered structure, and the contact angle of the coating is higher than 150° and the roll-off angle is lower than 10°. Sandpaper abrasion tests and UV diffuse reflectance spectra indicate that the coatings have excellent abrasion resistance and good transparency. In addition, the coated wood shows excellent self-cleaning and water resistance, which have great potential for applications in industry and furniture manufacturing.

Construction of Multifunctional Hierarchical Biofilms for Highly Sensitive and Weather-Resistant Fire Warning

Multifunctional biofilms with early fire-warning capabilities are highly necessary for various indoor and outdoor applications, but a rational design of intelligent fire alarm films with strong weather resistance remains a major challenge. Herein, a multiscale hierarchical biofilm based on lignocellulose nanofibrils (LCNFs), carbon nanotubes (CNTs) and TiO2 was developed through a vacuum-assisted alternate self-assembly and dipping method. Then, an early fire-warning system that changes from an insulating state to a conductive one was designed, relying on the rapid carbonization of LCNFs together with the unique electronic excitation characteristics of TiO2. Typically, the L-CNT-TiO2 film exhibited an ultrasensitive fire-response signal of ~0.30 s and a long-term warning time of ~1238 s when a fire disaster was about to occur, demonstrating a reliable fire-alarm performance and promising flame-resistance ability. More importantly, the L-CNT-TiO2 biofilm also possessed a water contact angle (WCA) of 166 ± 1° and an ultraviolet protection factor (UPF) as high as 2000, resulting in excellent superhydrophobicity, antifouling, self-cleaning as well as incredible anti-ultraviolet (UV) capabilities. This work offers an innovative strategy for developing advanced intelligent films for fire safety and prevention applications, which holds great promise for the field of building materials.

Chitosan-based coatings with tunable transparency and superhydrophobicity: A solvent-free and fluorine-free approach by stearoyl derivatization

One of the current greatest challenges in materials science and technology is the development of safe- and sustainable-by-design coatings with enhanced functionalities, e.g. to substitute fluorinated substances raising concerns for their potential hazard on human health. Bio-based polymeric coatings represent a promising route with a high potential. In this study, we propose an innovative sustainable method for fabricating coatings based on chitosan with modified functionality, with a fine-tuning of coating properties, namely transparency and superhydrophobicity. The process consists in two main steps: i) fluorine-free modification of chitosan functional groups with stearoyl chloride and freeze-drying to obtain a superhydrophobic powder, ii) coating deposition using a novel solvent-free approach through a thermal treatment. The modified chitosan is characterized to assess its chemico-physical properties and confirm the functionality modification with fatty acid tails. The deposition method enables tuning the coating properties of transparency and superhydrophobicity, maintaining good durability.

Flexible biomimetic materials with excellent photothermal performance and superhydrophobicity

Although thousands of superhydrophobic composites have been reported, it is still a challenge to develop eco-friendly superhydrophobic materials by a simple and low-cost strategy. Here, a paper-based superhydrophobic material was prepared by carbon fiber powders and polydimethylsiloxane through a facile spraying method. This obtained material has excellent liquid resistance and self-cleaning properties, whose contact angle reaches 155°. In addition, it possesses excellent photothermal conversion characteristics with a stable surface temperature of 73.4 °C and good water evaporation performance with an evaporation rate up to 1.08 kg/(m2·h) under one solar intensity (100 mW/cm2). Also, it has outstanding self-deicing performance, whose deicing time is 120 s earlier than that of the untreated surface under one solar intensity. An adaptability test shows this strategy of functional coatings can also be applied to other fiber substrates (coating paper, kraft paper, non-woven fabric, paulownia veneer, etc.). Overall, this superhydrophobic material has a promising application prospect in many fields such as waterproof packaging, deicing materials, water evaporation materials, etc.

Facile Preparation of PET/PA6 Bicomponent Microfilament Fabrics with Tunable Porosity for Comfortable Medical Protective Clothing

Medical protective materials have broadly drawn attention due to their ability to stop the spread of infectious diseases and protect the safety of medical staff. However, creating medical protective materials that combine excellent liquid shielding performance and outstanding mechanical properties with high breathability is still a challenging task. Herein, a polyester/polyamide 6 (PET/PA6) bicomponent microfilament fabric with tunable porosity for comfortable medical protective clothing was prepared via dip-coating technology and an easy and effective thermal-belt bonding process. The dip coating of the C₆-based fluorocarbon polymer endowed the samples with excellent hydrophobicity (alcohol contact angles, 130-128°); meanwhile, by adjusting the temperature and pressure of the thermal-belt bonding process, the porosity of the samples was adapted in the range of 64.19-88.64%. Furthermore, benefitting tunable porosity and surface hydrophobicity, the samples also demonstrated an excellent softness score (24.3-34.5), agreeable air permeability (46.3-27.8 mm/s), and high hydrostatic pressure (1176-4130 Pa). Significantly, the created textiles successfully filter aerosol from the air and display highly tensile strength. These excellent comprehensive performances indicate that the prepared PET/PA6 bicomponent microfilament fabrics would be an attractive choice for medical protective apparel.